Re: Release candidate for Qhull 2012.1

[Ben Abbott]

On Jan 29, 2012, at 11:34 PM, Dmitri A. Sergatskov wrote:

> On Sun, Jan 29, 2012 at 10:28 PM, Ben Abbott <address@hidden> wrote:
>> What doesn't make sense to me is that Octave sets it's on defaults, and in 
>> this instance the default is "Qt". With qhull < 2011 I get the Fedora result.
>> 
>> Can someone on Fedora (specifically qhull-2003) try ...
>> 
>>         cube = [0 0 0;1 0 0;1 1 0;0 1 0;0 0 1;1 0 1;1 1 1;0 1 1];
>>        [h, v] = convhulln (cube, {"Qt", "FO"})
>> 
>> ... and tell us what the result is ?
>> 
>> Ben
> 
> octave:1>  cube = [0 0 0;1 0 0;1 1 0;0 1 0;0 0 1;1 0 1;1 1 1;0 1 1];
> octave:2> [h, v] = convhulln (cube, {"Qt", "FO"})
> Options selected for Qhull 2003.1 2003/12/30:
>  Qtriangulate  _pre-merge  _zero-centrum  _max-width  1
>  Error-roundoff 1.4e-15  _one-merge 9.7e-15  _near-inside 4.9e-14
>  Visible-distance 2.8e-15  U-coplanar-distance 2.8e-15  Width-outside 5.5e-15
>  _wide-facet 1.7e-14
> h =
> 
>   4   1   2   3
>   5   6   2   1
>   8   5   1   4
>   6   7   3   2
>   7   8   4   3
>   8   7   6   5
> 
> v =  1

Thanks Dimitri. It looks to me as if the qhull versions prior to 2011 (at least 
2003, 2009, and 2010) did not return the correct result.

With 2011 or 2012, the hull is triangulated.

cube = [0 0 0;1 0 0;1 1 0;0 1 0;0 0 1;1 0 1;1 1 1;0 1 1];
[h, v] = convhulln (cube, {"Qt", "FO"})
Options selected for Qhull 2011.2 2011/11/29:
  run-id 1869887359  Qtriangulate  _pre-merge  _zero-centrum  _max-width  1
  Error-roundoff 1.4e-15  _one-merge 9.7e-15  _near-inside 4.9e-14
  Visible-distance 2.8e-15  U-coplanar-distance 2.8e-15  Width-outside 5.5e-15
  _wide-facet 1.7e-14
h =

   3   4   2
   2   4   1
   6   2   1
   5   6   1
   4   8   1
   8   5   1
   7   3   2
   6   7   2
   7   4   3
   7   8   4
   7   6   5
   8   7   5

v =  1

I've pushed a changeset to the default branch.

        http://hg.savannah.gnu.org/hgweb/octave/rev/2633baa831e2

Ben